Volkswagen's 261-MPG Diesel-Electric | Hacker News Reader

Volkswagen's 261-MPG Diesel-Electric

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82 pointsdpcx88 comments

Clinton was working with the major auto manufacturers to do this years ago. Each of the big four had models designed and tooling up the plants for production was to be subsidized.

Bush came in and killed the program in favor of the yet to materialize hydrogen.

Not really commenting on your appreciation (I don't really know the details of Clinton-Bush-Obama's politiques on electric/hydrogen automobiles) but in the university where I studied some of my department-mates were working on fuel cells and their applications.

One of the most interesting (for me) applications was hydrogen fuel cell vehicles, and I could talk with some of the students involved in that research about the current state of the technology. I was also fortunate enough to test one of the vehicles they were using. While I still don't know the technical details, they mentioned that the main reason the technology is not yet available (I think Toyota wants to have an hybrid by the end of 2015) was the lack of investment or the shift of investment to battery powered vehicles.

What was more interesting to me is that the difference between an electric car and a hydrogen fuel cell vehicle is basically the source of energy used. With that I don't mean the technology if fully ready; as far as I know there are still concerns beyond logistics (for example, temperature problems, security...) but I would say those are part of the novelty of a technology.

Interesting, do you have any references/links with more info about that?

Volkswagen has been doing interesting things with diesel for a while now. Back in 2005, they introduced the turbo diesel powered Audi R10, which won the 2006 12 Hours of Sebring and 24 Hours of Le Mans. It was replaced in 2011 by another turbo diesel, the R18.

Of course, neither of these are diesel/electric hybrids, but it's not a surprise that, given their history of inovation with diesel, Volkswagen Group put something like this together.

Actually, the R18 is available as a diesel/electric hybrid! It's know as the R18 e-tron quattro and the electric motor separately powers the front wheels, converting the R18 to a quattro (4-wheel drive system). Because of the race rules and regs though, the electric is only allowed to kick in past 120km/h.

>Because of the race rules and regs though, the electric is only allowed to kick in past 120km/h.

Why make that rule?

The R18 e-tron sends the extra power to the front wheels (effectively making it a four wheel drive). I guess the rule was put in place to negate any advantage the R18 e-tron will have when cornering.

The other LMP hybrid is the Toyota TS030, their system applies the extra power at the rear only, and therefore Toyota can use the electric power at any speed (race reports of the 2012 24 hr of Le Mans said that the Toyota TS030 was eerily silent going down the pit road as it was running on pure electric power on pit stops).

Of course the R18 Etron is a Flywheel based system, which has little relevance to road cars. it's Also caped at 500Kj of energy that can be stored and released per braking.

IMO that rule was made to prevent the cars from going through slow corners too fast, The speed restriction only applies to cars that have the motors connected to the front wheels. The Toyota cars have their hybrid motors attached to the rear and they can use their hybrid system from 0 kmph.

Presumably because of the torque an electric motor can make off the starting line, versus an ICE.

huh! I didn't know that. I'm haven't been keeping up LMP development (since about 2007/08). Cool to know, though

Yeah I was happy to see a nicely priced Jetta Hybrid; but for some reason it's a gas/electric.

I would have thought they'd do diesel/electric since they already do a a Jetta TDI.

"The result is a car that weighs just over 1,900 pounds, or about one-third less than the new 911."

And 10% more than a 1963 Beetle of fifty years ago.

http://www.hemmings.com/hsx/stories/2007/04/01/hmn_feature23...

I've always thought this.

Mk1 Golf GTI was very light: 790kg, as was the Mk2 Golf GTI 910kg (hot hatches from Europe) but ever since then cars seem to be minimum 1,200kg. They are a lot safer and that is the main reason. You can walk away from a minor crash with your legs intact.

Car manufacturers have been upping power (speed) over the years and this has lead to an increase in weight from a performance and reliabilty standpoint but also safety.

With lots more comfort, safety equipment, etc. Seems like a valid tradeoff to me :)

That's only a couple hundred pounds lighter than my Miata, which has an empty weight around 2050 lbs.

Granted, the Miata doesn't have anywhere near the Cd that the VW has.

It does have more in the way of safety and comfort features though.

At zero to sixty in twelve seconds, however, it's not appreciably quicker off the line...well, ok, significantly faster if we use a 1963 Type II.

I thought we were done with the ugly "covered up rear wheels for electric cars" thing.

It's unfamiliar, not ugly. Give it a few years and you'll think they're perfectly fine, just like we heard endless complaints about "melted" cars when more aerodynamic designs were first introduced.

(partially) covering the wheel doesn't have to be as ugly as it is in this particular VW. I submit the first generation Plymouth Fury as evidence:

http://en.wikipedia.org/wiki/Plymouth_Fury

Ugly or not, covering up the rear wheels can give a meaningful improvement to fuel economy.

An early Saab also had covered front wheels, to improve economy. It was problematic though because it under certain conditions it could get packed with snow and hinder turning.

Curious to see how that could possibly look, I scrounged up these pictures of a 1947 Saab prototype. Beautiful.

http://www.thelocal.se/gallery/news/806/

wow. That, is a beautiful car.

With wheel no more than a few inches wide, it won't be driving in the snow anyway.

Actually unless you're trying to drive on TOP of feet of snow, narrow is better than wide for normal driving as you cut through the snow and get to the road. Typically people will run snow tires that are 10mm narrower than their summer tires on the same rims.

Well, the request was simply to see some data on how "meaningful" the improvement is.

I think the covered up rear wheels are not just a optical gimmick, but safe fuel.

It looks kind of sexy (and expensive)!

Probably the expensive part is true. :(

The car may be expensive, but covered rear wheels are not expensive.

It's hideous; I agree. The prevailing argument here for the covers is fuel economy (i.e. reduced drag). Show me the numbers with and without the covers, but, I'd bet they're not so different that I'd sacrifice the look of the automobile by adding them, especially considering the 250+ MPG claim here.

Here are some stats: 0.4-6.25% http://ecomodder.com/wiki/index.php/Rear_wheel_skirts

It's highly dependent on speed.

Small gains can add up. I had a 75 minute commute for a while and ran some MPG experiments on my truck. Adding a wedge shaped tonneau cover, a chin spoiler, and inflating the tires more boosted my MPG from 18-26. It was ugly so I took them off and got distracted before I built them again. It was much quieter and seemed to "roll" along at faster speeds.

HN is certainly not the place I expected to find a comment criticizing the aesthetics of a useful engineering decision.

I'm excited to see a car that was actually designed up-front with aerodynamics in mind. This isn't the first of course but they're pretty rare. Even for the Bugatti Veyron and Nissan Leaf, where you'd think drag forces would be the first consideration for the body, the overall look was determined first and aerodynamic engineers had to work within those limits.

I don't know about the Bugatti, but think of the use case for a Leaf -- urban commuting and errands. Does aerodynamics matter for city driving?

Here in snow country, the last thing I would want is for my wheels to be covered like that.

Not everything is snow country and it might make perfect sense in warmer or more densely populated places.

There’s no reason why one car would have to be fit for every climate on every continent.

I figured someone would make that comment. I'm just giving one example of why this may not be a good engineering decision. It also makes it hard to access or inspect the wheel/tire in general. You can't just optimize for one thing like aerodynamics without taking into account the big picture (and I personally think aesthetics). I have seen many solar cars and high efficiency cars over the years that are highly impractical because they've optimized one efficiency dimension too far.

Of course you have to take maintenance and aesthetics etc. into account, but depending on your target market and the value you put on fuel efficiency, you can still come to the conclusion that covered wheels are the way to go for this particular vehicle.

Nobody would put covered wheels on some off-road car, mostly because these aren’t exactly known for efficiency in the first place.

Aesthetics have a lot to do with building a successful car. A simple example? The VW New Beetle shares the same platform as the Jetta, but ask 100 men if they would own one.

Sure, but the extremely dismissive tone of "lol ugly" is not at all what I'd expect from a crowd interested in building great things.

I feel that Tesla's success with the Model S is due to its fairly conventional shape. It looks like an "ordinary" car.

I'm not sure if the design aspects of this VW are due to improved aerodynamics, or a desire to make something look "futuristic". Striving for this look actually makes it feel out-of-date.

Here's your answer: "The XL1 has a coefficient of drag of 0.189" from the article.

That's an enormous improvement on all other production cars. Which is why it uses " 8.3 horsepower to maintain [60 mph]— one-third that of a Jetta"

Of course, they don't mention the frontal area, which is just as important and yet never referenced in these discussions.

Well, it has a conventional shape, but it also looks distinct. I think trying to make an electric car that looks just like any other car would be a mistake- I came to this conclusion after looking at the Prius and the Insight.

See, the Insight was too weird and too much of a compromise (2 seater, stickshift), so even though it got 70MPG in the 90's, it never took off. Nor did the first generation Prius, which looks exactly like an ordinary car. Then the second generation comes along, which is much like an ordinary car but has a distinctive look that says "Look at me! I'm driving a Prius!" and it sold like hotcakes.

My conclusion is essentially that people were uninterested in hybrids, unless the hybrid was recognizable as such to act as a social signal, yet did not compromise on any of the functionality of a regular car. So in summary, the Tesla does these things- it has a distinctive look, enough to signal "Look at me! I drive a Tesla!" while still being very close to an ordinary car.

> the Insight ... got 70MPG in the 90's

I was a fan of the original Insight... the real-world MPG was actually around 38 IIRC. There were a couple gas-only cars with better MPGs and fewer compromises (i.e. back seats).

> I think trying to make an electric car that looks just like any other car would be a mistake

Additionally: the Chevy Volt. The pre-production cars looked amazingly futuristic, and the production car looks like every other Chevy. The incredibly boring appearance is, honestly, one of the things that lowered my interest in the car.

With respect to sexy styling, they're damned if they do and damned if they don't. I agree that Tesla threaded that needle almost perfectly.

You can look up real world MPG on a site like fuelly.com. It looks like the first gen Honda Insight is over 55 MPG on average. There aren't enough cars to get a great sample but they list about 75 cars between 2000-2006.

You are both right -- they reduced the efficiency of the engine in the later models; see:

http://www.plasmaboyracing.com/blog/?p=124

It's not a convential shape since it uses gullwing doors.

It looks like an "ordinary" car.

It looks like a hot car. Not only is it functionally awesome, it looks awesome. This is a car that people would want to not only drive but be seen driving.

Let's be honest, most people will buy a car based on how it looks. Sure, fuel economy, size, utility, and how it fits you lifestyle all matter, but if there's 2 cars that are somewhat the same but one looks better to the purchaser they are most likely going to buy the car that looks the best. Sometimes even if it doesn't have everything they need.

I don't need a Tesla Model S but I would buy one if I had the disposable income. I don't need a Dodge Challenger but I'd buy one if I had the disposable income. Both of those vehicles I find hot.

With a 250 unit production run I don't think VW is going for huge commercial success with this one.

"The car doesn’t need much power due to its wind-tunnel honed bodywork. The XL1 has a coefficient of drag of 0.189 — making the uber-slick Tesla Model S look a bit like a brick — and is the most aerodynamic production car on the planet."

Same for the Opel Amera. Opel cars are always ugly. But Amera looks like it's out of a low buget SciFi film.

But I think this car looks like all the next gen VWs will look like. We will get used to it.

I drive a diesel, and I love it. I'm so surprised that all of these hybrids are "revolutionary" yet they offer almost no improvement over something similar with a diesel engine.

My 1.9L diesel engine gets 40+ MPG everyday for the past few years. I'm excited by what Mercedes is doing with their GLK250... a 2.1L diesel in the GLK is almost perfect for that car.

40MPG vs 260MPG is not exactly "similar" though.

Something like a Prius vs a modern diesel though is very similar, I don't see the Prius as revolutionary.

I wasn't comparing a normal car to this, as this is an edge case.

I am talking about the choices we make when purchasing a car. Almost everyone that I spoke to that has a hybrid doesn't consider it worth the money. These manufacturers advertise "38MPG highway" as being something incredible while a ten year old technology can achieve something better.

The problem is that gas prices are stable (controlled?) in the US so that inefficient cars are the norm.

The planetary gear transaxle is innovative, if not revolutionary. It solves the problem of power delivery in a completely different way from the traditional gears + clutch/torque converter.

You have to be really careful when talking about fuel economy. The numbers mean one very specific thing, on a particular test the car achieved a particular fuel economy. Without specifying how exactly they got those fuel economy numbers(referring to article), the numbers are literally meaningless. If I'm just cruising along at 60mph on flat land I can get 65mpg in my gen2 prius, even though the official highway number is 45mpg.

Driver behavior, AC, the test conditions, and vehicle conditions all affect efficiency.

With the proper driving strategy the prius can great efficiency out of situations that are problematic for traditional vehicles. What kind of fuel economy do you get out of your diesel in stop-and-go traffic? With regenerative braking and the ability to turn off the engine when not needed can easily get 75mpg+. On the freeway with the cruise set at 70mph (cruise control is not optimal) I get about 53MPG.

The 2009 Prius I drive has an official US combined MPG of 46. On average I get 55 MPG. The regenerative braking has great potential, if you drive in a way that takes advantage of it by planning your stops.

If you look at the numbers:

40 MPG is 5.88 l/100km 55 MPG is 4.28 l/100km

(5.88 - 4.28)/5.88 = 27%

The prius is 27% with my numbers and that's against a fuel that is 11% more energy dense.

If your numbers are based on the on-board computer, they're wrong. The computer usually states something higher than what you actually get. Even the MPH is a lie, as the speedometer is set to be higher by 3-9 MPH.

In the real world, I haven't seen hybrid drivers that actually get what's advertised. I don't know how much this has changed within the last 3 years...

I've calculated the long-term average by tracking how much fuel I put in the tank and how much the odometer goes up, over many fillups. From that I get about 55mpg.

The efficiency in specific situations is from the on board computer.

How do you calculate it?

> In the real world, I haven't seen hybrid drivers that actually get what's advertised

Come over to priuschat.com sometime and you'll find plenty of them that get the advertised numbers and better.

EDIT: Or check out fuelly, which calculates efficiency using the same method and you'll find plenty of people who get better than the official numbers: http://www.fuelly.com/car/toyota/prius

Wow! I never thought about looking at how much I've spent on fuel over a long period of time. The problem for me is that we have multiple cars.

I currently drive until the red light comes on, fill up, and look at the trip counter to see how many miles I've driven since my last fill-up. I then reset the trip counter and repeat. My time is spent in mixed highway and city traffic.

I'll have to look at modern hybrids once something actually breaks on my car. I'll consider everything equally once it's time to shop again.

They aren't really revolutionary, of course, but a gasoline powered hybrid still has a slight efficiency edge over a diesel. If you factor in the higher complexity, weight, cost and emissions of Diesel vs. Otto it's easy to see why gas hybrids are popular today.

I think what VW and Bosch are doing for diesels will pave the way for broad adoption of diesel-hybrids at some point, though.

I'm curious, how do gas hybrids have an edge?

If you consider reliability, a diesel has no "technology", so there are fewer things to go wrong.

The issue of emissions has been addressed with BlueTec. No?

* Reduced wear-tear on ICE engine (my Prius can idles on downslopes at 70mpg+ not to mention during low speeds) - I change oil every 12 months (synthetic) and it's always clear.

* No transmission - eCVT = engine directly mated to front transaxle.

* No need for ultra-low-sulphur diesel fuel (I couldn't buy a turbo-diesel in CA a few years ago), or even finding a station that sells diesel (most do, some do not).

* No evaporative emissions = garage smells cleaner.

* Regenerative breaks = no breakpad replacements in 8 years.

* No smog check - still haven't had to do one.

You also get a zen feel when you drive a car that's using electric - it floats forward, no rumble beneath your feet, in 2005 I couldn't buy any other car that'd give me that feeling and also seat 5 ppl comfortably.

I like turbo-diesels, but I like my gas hybrid better.

Modern diesels have tons of "technology." When you're running pressures above 40,000 PSI on the common-rail and doing direct injection, there's quite a lot of tech in a modern diesel engine. Older, dirtier, diesels don't need this tech but emit quite a lot more particulates and other unwelcomed emissions.

Any of the urea injection technologies are a pain. Some modern diesels have low enough emissions to not need the urea. We need more of those and less urea.

"Edge" I meant purely in terms of fuel efficiency. If you consider the average consumer looking at buying a passenger car they might be willing to spend a premium on a more efficient car. Two common choices are a modern diesel or gas hybrid. At least here in the US the hybrid is a slightly more attractive choice if you factor in the purchase price and the price of diesel.

The reason Diesel hasn't caught on with the eco-crowd is pretty simple: particulate.

PSA Peugeot-Citroen have been selling diesel-electric hybrids for more than a year now:

http://en.wikipedia.org/wiki/Peugeot_3008#Hybrid_version

http://www.carmagazine.co.uk/Drives/Search-Results/First-dri...

If the diesel can run on vegetable oil, you could grow a year's supply of fuel with 1 acre of sunflowers. Storage would not be a problem, either. That's a cheaper way to access solar energy for driving than an acre of solar panels.

1 acre of PV != 1 acre of biofuel crops. Biofuels require at least 20x more area. If we stopped growing all food we could just about cover our energy needs with biofuel. PV is the way to go.

http://thinkprogress.org/climate/2013/03/27/1783781/for-powe...

As for actual cost, SolarCity's business model seems to indicate that the net present value of solar is cheaper than residential grid electricity, which is in turn cheaper than gasoline/diesel. And solar prices keep plummeting.

Let's see how that works out. Wikipedia says there are 240 million cars in the US. That means we would need 240,000,000 acres of sunflowers to power all our cars. World Factbook says the US has 9,161,966 sq km of land of which 16.29% is arable or 1,492,484 arable sq km. With about 247 acres per sq km, we have 368,643,612 acres of arable land which means about 65% of the arable land in the US would have to be devoted to sunflower production.

On the other hand, those solar panels can go anywhere.

Is this accounting for all the labor and resources it takes to grow and process the sunflowers?

My yard is mostly sand, and it's still harder not to grow sunflowers. Not sure about processing, but growing them won't be a problem.

Back-of-the-envelope, probably comparable to cutting and splitting firewood for heating.

Yeah but what about the pollution (not CO2)?

I really like the look of the car, I have always loved the slick aerodynamic "futuristic" look. I also keep wondering why commercial long haul trucks have such an inefficient design. It's like a giant block barrelling down the highway. Couldn't a little bit of aerodynamics go a long way for long haul truckers ?

They do. See:

[1] Between the back tires is a flap that helps with aerodynamics. I would say that 50%+ of the trucks I see on the road have these.

[2] These are much less common, but I'd guess 5% or so use these.

[1] http://www.popularmechanics.com/cm/popularmechanics/images/p...

[2] http://www.blogcdn.com/green.autoblog.com/media/2009/11/part...

that's really cool I never saw that before.

The Wal Mart supercube trucks are an example, http://www.core77.com/blog/transportation/walmarts_new_super...

Also, note that its not just the truck, but how you pack it and how you package what it is carrying http://www.walmartgreenroom.com/tag/trucks/

* I do not work for Wal Mart, merely remember articles about their fleet recently

Interesting,I always expect the snub nose of these drags to add a lot of drag and keep expecting them to become more smooth and conical. But I'm sure these methods are more cost effective.

Careful with the numbers. With hybrids, they often don't count the electricitiy in the consumption, but still measure with the car running on it. That leads to these rather outrageous numbers of 261MPG - they just assume electricity is free. Using that measurement, of course the Tesla Model S has infinite MPG.

Tesla Model S would have an undefined MPG. The limit approaches infinity for very small values of G, but isn't defined for a value of 0.

They assume electricity is 'free', because the battery is charged only by the fuel in a hybrid. (Not a plug-in hybrid of course). So there is no need to consider the electricity as a separate cost. Or am I misunderstanding what you're saying?

Most hybrids with a larger battery (as this one) also have a charging port. I think what they do is start the test with a fully charged battery and never count the energy in that. So you get the first 40 miles or so free until the motor kicks in to recharge the battery again (which is where they then start counting the gasoline consumed).

>the XL1 can putter along for 32 miles and at up to 62 mph on electric power alone

I wonder what kind of numbers they could get out of an electric-only version. 62mph is near the legal limit of highway speed anywhere I've ever been, so for me that would be a fine limitation. If they removed the diesel engine, the extra drive-train components it requires, and the gas tank, they could save more weight. With just that weight savings, the range would be improved. It also leaves room for installing a larger battery. 32 mi on a 5.5 kWh battery is nice, but of course the public wants more. For reference, the Tesla S with the largest battery option (85 kWh), can do 265 mi.

It is good to see a car company pursuing a radical design.

Mind you that 62 mph is probably on flat ground. The moment you have to deal with hills, 62mph flat out is going to get you in trouble. And yes, I know highways are typically pretty flat, but even small grades can result in large increases power required.

In the future, fuel-efficient cars will look like normal cars! I can't wait. Hopefully it will be because the people making them realize that fuel-efficient cars don't need to look like rejected drawings from Doug[1] and not that everyone decided that all cars need to look like rejected drawings from Doug.

[1] http://i986.photobucket.com/albums/ae342/dougfunnieiscrazy/D...

I've been hoping to some day find a car that is a worthy replacement for my Honda Insight. The Volkswagen seems to be similar in many ways: comparable horsepower, weight, covered rear wheels, etc. I doubt it'll be $22,000 though.

A friend even was able to get similar mpg numbers by boosting the battery pack to a similar capacity (in a competition). Too bad the market didn't shine on the early Insight. If I remember correctly, they only sold 20,000 worldwide over its 8 year run.

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